There have long been various forms of cups and bottles designed to meet the particular specific or specialized drinking needs of various groups of people. For example, the “baby bottle”, wherein liquid is drawn through a “nipple” of some form, is designed for use by infants that are just learning to handle and drink liquids and that may not yet be capable of drinking in the more conventional sense, but only of drinking by “sucking”. As is well known, drinking by “sucking” requires not only that an infant be able to suck liquid from a bottle, but also that a means be provided to vent air into the bottle so that the infant does not ingest excess air. In addition, the operation of the liquid and air “valve” or “valves” must be passive as infants are not capable of actively operating a valve and, because infants are typically not yet capable of handling a cup or bottle, the bottles must be designed to prevent spills, even when the bottle is dropped or is lying on its side.
Yet another type of bottle or cup are those designed for use by completely capable people that for some exterior reasons, such as being engaged in athletic activity of some form, require a bottle that is spill-proof or spill-resistant, even when shaken, dropped, turn upside down, and so on. Such people are capable of operating a relatively complex spill resistant valve mechanism, and a range of satisfactory designs for such are well known.
There remains, however, a third class of bottles or cups that are intended for persons who are not as limited as infants, but that still require or would benefit from a cup or bottle that provides some assistance in drinking from the cup or bottle. The users of such bottles and cups may include, for example, “toddlers” and other young children past the infant stage, and adults who are handicapped in some manner, such as by age or illness. In such instances, the user will be “drinking” from the cup rather than “sucking”, but the requirement that the cup or bottle be spill-proof or spill-resistant when dropped or positioned at a large angle still applies, as does the requirement that any valve or mechanism be simple to use and passive in operation, that is, that it does not require active operation by the user.
Still other requirements are that the spill resistant valve mechanism be simple and inexpensive to manufacture, that the valve provide a smooth and reliable outward flow of liquid and inward flow of air, that the valve allow relatively complete drainage of the cup or bottle, and that the valve be easy to clean. It is also advantageous if the flow of liquid and air by the valve has no abrupt “steps” or “surges”, but instead smoothly increases from a relative small starting flow to a large maximum flow, and if the valve does not require excessive “force” or suction to operate.
The present invention provides a solution to these and other related problems of the prior art.